A short-process waste lithium cobalt oxide positive electrode material nondestructive separation and regeneration method

Abstract

The application discloses a short-process waste lithium cobalt oxide positive electrode material nondestructive separation and regeneration method, and relates to the technical field of comprehensive utilization of secondary resources.The application obtains a waste lithium cobalt oxide positive electrode material solution and a current collector by separating a waste positive electrode sheet through a eutectic solvent; after the current collector is taken out, lithium source, nickel source and manganese source required for synthesizing lithium nickel manganese oxide are supplemented into the waste lithium cobalt oxide positive electrode material solution, then the lithium source is precisely embedded into lithium vacancies of the waste lithium cobalt oxide through a sol-gel method and a solid-phase calcination method, and in-situ coating of micron-level lithium nickel manganese oxide is realized, so that the problems of material damage, lithium loss and secondary pollution caused by traditional high-temperature calcination or pickling process are solved, and efficient regeneration of the waste lithium cobalt oxide positive electrode material is realized.In actual application, compared with traditional pyrometallurgical and hydrometallurgical recovery processes, the application has lower cost, better commercialization potential, and can provide an innovative solution for green recycling and large-scale application of power batteries.

Description

Technical Field

[0001] This invention relates to the field of secondary resource comprehensive utilization technology, and in particular to a short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials. Background Technology

[0002] Currently, the amount of scrapped lithium cobalt oxide (LiCoO2) batteries is increasing dramatically. However, its efficient recycling faces a core bottleneck: the layered structure of the cathode material undergoes an irreversible phase transition during long-term cycling, with cobalt ions migrating to lithium sites to form the rock salt phase CoO, accompanied by lattice oxygen precipitation and dense accumulation of the surface passivation layer, severely hindering the performance of recycled materials. Structural collapse not only leads to blockage of lithium ion transport channels (resulting in the initial coulombic efficiency of the recycled cathode being <85%), but also causes chemical instability of cobalt, which easily generates inert phases such as Co3O4 during pyrometallurgical recycling, causing the loss of valuable metals, or increases the risk of wastewater toxicity due to cobalt leaching during wet leaching. Existing technologies for addressing this problem all have significant drawbacks: while high-temperature calcination can reconstruct the layered structure, it causes LiCoO2 to decompose into electrically inactive cobalt oxides, leading to significant lithium volatilization and high energy consumption; wet acid leaching, although capable of selective extraction of cobalt, causes an imbalance in the stoichiometry of the material due to the unexpected dissolution of valuable metals by strong acids, and generates acidic wastewater with high concentrations of cobalt; while pure mechanical activation avoids the use of chemical reagents, the high lattice distortion energy barrier results in a structural disorder degree greater than 40%, and excessive pulverization leads to particle agglomeration and decreased compaction density. Although recent studies have attempted improvements, such as using N-methylpyrrolidone solvent (NMP), the inherent high toxicity and volatility of the solvent itself have consistently prevented it from crossing the threshold for large-scale application. In summary, the industry urgently needs a closed-loop recycling solution that combines low temperature, precision, environmental protection, and large-scale operation. Under mild conditions, this solution can achieve separation of cathode materials and current collectors through multi-field coupling, while simultaneously performing in-situ ordered repair of the LiCoO2 lattice and reversible transformation of the surface rock salt phase. This would fundamentally resolve the contradiction in traditional processes where "reconstruction inevitably results in loss of value and regeneration inevitably results in high consumption," and promote the leap from "extraction of valuable metals" to "restoration of intrinsic material properties" in battery regeneration. Summary of the Invention

[0003] The purpose of this invention is to provide a short-process, non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials to solve the problems existing in the prior art. This invention first uses a eutectic solvent (DES) to separate the waste lithium cobalt oxide cathode material from the current collector, and then regenerates the waste lithium cobalt oxide cathode material by coating it with lithium nickel manganese oxide. This achieves efficient separation of waste electrode sheets from the waste lithium cobalt oxide cathode material while simultaneously removing residual polyvinylidene fluoride (PVDF), repairing the layered structure and compensating for lithium, and achieving high-value regeneration through lithium nickel manganese oxide coating.

[0004] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention: a short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials, comprising the following steps: The positive electrode sheet recovered from the waste lithium cobalt oxide battery is heated and soaked in a eutectic solvent (DES) to separate the waste lithium cobalt oxide positive electrode material from the current collector. After the current collector is removed, a solution of waste lithium cobalt oxide positive electrode material is obtained. A remediation and regeneration solution containing nickel, manganese, and lithium is added to the waste lithium cobalt oxide cathode material solution, heated and stirred, and then the pH of the mixed solution is adjusted to 6-9 before being heated to volatilize, resulting in a mixed colloid. The mixed colloid is dried, ground, and then calcined to obtain recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material, thus achieving non-destructive separation and regeneration of waste lithium cobalt oxide cathode material.

[0005] This invention first utilizes DES to separate waste lithium cobalt oxide cathode material from the current collector, and then regenerates the waste lithium cobalt oxide cathode material by coating it with lithium nickel manganese oxide. Specifically, in the electrode separation stage, DES, as a green medium, can selectively attack the hydrogen bond crosslinking points of PVDF within a mild temperature window of 60-120 °C, achieving non-destructive separation of waste lithium cobalt oxide cathode material from the current collector. The pH environment of 6-9 fundamentally inhibits heavy metal leaching, significantly reducing the burden of wastewater treatment. The biodegradable component design of DES, combined with its high boiling point characteristics, completely eliminates the health hazards of the NMP method. Compared with traditional electrode separation technology, this method reduces the step of calcining the electrode to collect the current collector and waste lithium cobalt oxide cathode material, demonstrating significant advantages. In the process of lithium nickel manganese oxide coating regeneration, the lithium nickel manganese oxide precursor and supplementary lithium source colloid prepared by the sol-gel method can be uniformly attached to the surface of waste lithium cobalt oxide cathode materials, thereby achieving in-situ regeneration and repair of waste lithium cobalt oxide cathode materials. This solves the problems of material damage, lithium loss, and secondary pollution caused by traditional high-temperature calcination or acid washing processes, and also achieves efficient regeneration of waste lithium cobalt oxide cathode materials. Moreover, the in-situ coating of lithium nickel manganese oxide on the surface of waste lithium cobalt oxide cathode materials can also inhibit cobalt dissolution and interfacial side reactions under high voltage, improve the cycle stability and thermal safety of the regenerated materials, and improve the electrochemical performance of the regenerated materials by utilizing its three-dimensional ion channels.

[0006] Furthermore, the steps for recycling positive electrode sheets from waste lithium cobalt oxide batteries include: disassembling the waste lithium cobalt oxide batteries after deep discharge and stripping off the positive electrode sheets.

[0007] Furthermore, the deep discharge specifically refers to discharging to a state of charge (SOC, or remaining charge) of ≤20%.

[0008] Furthermore, the hydrogen bond acceptors of the eutectic solvent include citric acid, salicylic acid, phytic acid, or lactic acid, and the hydrogen bond donors include ethylene glycol, xylitol, glycerol, or glycerol.

[0009] Furthermore, the mass ratio of the hydrogen bond acceptor to the hydrogen bond donor ranges from 1:2 to 1:4 (W / W).

[0010] Furthermore, the preparation step of the eutectic solvent includes: mixing the hydrogen bond donor and the hydrogen bond acceptor, and heating and stirring at 80°C until a clear and transparent solution is formed.

[0011] Furthermore, the temperature of the heating and soaking treatment is 60-120 ℃, and the time is 5-30 min.

[0012] Further, the preparation steps of the remediation and regeneration solution containing nickel (Ni), manganese (Mn), and lithium (Li) include: weighing the lithium source, nickel source, and manganese source of lithium nickel manganese oxide according to the molar ratio of metal elements Li:Ni:Mn=1.05:0.5:1.5 and the molar ratio of nickel element in the nickel source to cobalt element in the waste lithium cobalt oxide cathode material solution is 1:40; weighing the supplementary lithium source of the waste lithium cobalt oxide cathode material according to the molar amount of lithium element in the supplementary lithium source = (molar amount of cobalt element in the waste lithium cobalt oxide cathode material solution - molar amount of lithium element in the waste lithium cobalt oxide cathode material solution) × 1.05; and mixing the lithium source, nickel source, manganese source, and supplementary lithium source with anhydrous ethanol to obtain the remediation and regeneration solution containing nickel, manganese, and lithium.

[0013] In the above formula, the molar amount of cobalt in the waste lithium cobalt oxide cathode material solution represents the molar amount of cobalt contained in the waste lithium cobalt oxide cathode material, and the molar amount of lithium in the waste lithium cobalt oxide cathode material solution represents the molar amount of lithium contained in the waste lithium cobalt oxide cathode material.

[0014] Preferably, mixing the lithium source, nickel source, manganese source, and supplementary lithium source with anhydrous ethanol includes: first mixing the lithium source, nickel source, and manganese source with anhydrous ethanol, and then adding supplementary lithium source for mixing.

[0015] Furthermore, the lithium source includes one or more of lithium carbonate, lithium hydroxide, lithium oxide, lithium acetate, lithium nitrate, lithium oxalate, and lithium citrate.

[0016] Furthermore, the nickel source includes one or more of nickel oxide, nickel acetate, nickel nitrate, nickel oxalate, and nickel sulfate.

[0017] Furthermore, the manganese source includes one or more of manganese dioxide, manganese trioxide, manganese acetate, manganese nitrate, manganese oxalate, and manganese sulfate.

[0018] Furthermore, the supplementary lithium source includes one or more of lithium carbonate, lithium hydroxide, lithium oxide, lithium acetate, lithium nitrate, lithium oxalate, and lithium citrate.

[0019] Furthermore, adding the repair and regeneration solution containing nickel, manganese, and lithium to the waste lithium cobalt oxide cathode material solution includes: using a guide rod to slowly pour the repair and regeneration solution containing nickel, manganese, and lithium into the waste lithium cobalt oxide cathode material solution (the guide rate, i.e., the addition rate of the repair and regeneration solution, is 5-10 mL / min).

[0020] Furthermore, the heating and stirring temperature is 60-120 ℃, and the time is 10-30 min.

[0021] Furthermore, the heating and volatilization temperature is 60-100 ℃. The purpose of heating and volatilization is to evaporate the anhydrous ethanol in the regeneration solution, and to attach the lithium nickel manganese oxide precursor and supplementary lithium source to the surface of the waste lithium cobalt oxide cathode material through the sol-gel method, so that the lithium source can be precisely embedded into the lithium vacancies of the waste lithium cobalt oxide and micron-level in-situ coating of lithium nickel manganese oxide can be achieved during the subsequent calcination process.

[0022] Furthermore, the calcination treatment includes: heating to 800-1000 ℃ at a heating rate of 1-10 ℃ / min and then holding at that temperature for calcination for 10-24 h.

[0023] Furthermore, the calcination treatment is carried out in an oxygen-containing atmosphere.

[0024] Preferably, the oxygen-containing atmosphere is created by introducing high-purity oxygen at a flow rate of 150-250 sccm.

[0025] The second technical solution of the present invention: a recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material obtained by the above-described short-process waste lithium cobalt oxide cathode material non-destructive separation and regeneration method.

[0026] The third technical solution of the present invention: the application of the above-mentioned recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material in the preparation of lithium cobalt oxide batteries.

[0027] This invention obtains a waste lithium cobalt oxide cathode material solution and a current collector by separating waste cathode sheets using a eutectic solvent. After removing the current collector, a lithium source and the nickel and manganese sources required for synthesizing lithium nickel manganese oxide are added to the waste lithium cobalt oxide cathode material solution. Then, through the sol-gel method and solid-phase calcination method, the lithium source is precisely embedded into the lithium vacancies of the waste lithium cobalt oxide, achieving micron-level in-situ coating of lithium nickel manganese oxide. This solves the problems of material damage, lithium loss, and secondary pollution caused by traditional high-temperature calcination or acid washing processes, achieving efficient regeneration of waste lithium cobalt oxide cathode materials. In practical applications, this invention is lower in cost than traditional pyrometallurgical and wet recycling processes, has good commercial potential, and can provide an innovative solution for the green recycling and large-scale application of power batteries.

[0028] The present invention discloses the following technical effects: This invention utilizes a step-by-step synergistic technology of efficient separation by DES and in-situ regeneration of waste lithium cobalt oxide cathode materials (including in-situ remediation of lithium cobalt oxide and in-situ coating of lithium nickel manganese oxide), realizing an integrated direct regeneration method for waste lithium cobalt oxide cathode materials from sorting to regeneration. Taking advantage of the characteristics of DES—which can be directly synthesized at near-room temperature (around 80℃) and selectively attack the hydrogen bond crosslinking sites of PVDF within a mild temperature window of 60-120℃—it acts as a green solvent, achieving efficient separation of waste lithium cobalt oxide cathode materials and current collectors through multi-field coupling under low-temperature and mild reaction conditions. The reaction temperature is significantly lower than the high temperatures of over 500℃ required for traditional pyrometallurgical separation of electrodes. Furthermore, the strong coating properties and uniform coating effect of the sol-gel method allow lithium nickel manganese oxide and the lithium source to be uniformly distributed on the surface of the waste lithium cobalt oxide cathode material, achieving in-situ regeneration of the waste lithium cobalt oxide cathode material. The method of this invention has the core advantages of being "mild, precise, and environmentally friendly". While ensuring the electrochemical performance of recycled materials, it significantly improves the economic benefits of the entire process and is more in line with the technological upgrading needs of green manufacturing and circular economy under the goal of carbon neutrality. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The images show the XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in Example 1.

[0031] Figure 2 The image shows the XRD pattern of the lithium nickel manganese oxide cathode material synthesized by the sol-gel method in Example 1.

[0032] Figure 3 The images show the XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in Example 2.

[0033] Figure 4 The images show the XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in Example 3.

[0034] Figure 5 The XRD patterns of waste lithium cobalt oxide cathode material and recycled lithium cobalt oxide cathode material in Comparative Example 1 are shown.

[0035] Figure 6This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in Example 1 at a 1C rate.

[0036] Figure 7 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material at 1C rate in Example 2.

[0037] Figure 8 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in Example 3 at a 1C rate.

[0038] Figure 9 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at a 1 C rate in Comparative Example 1.

[0039] Figure 10 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at a 1 C rate in Comparative Example 2.

[0040] Figure 11 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material in Comparative Example 3 at a 1 C rate.

[0041] Figure 12 This is a comparison chart of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at a 1 C rate in Comparative Example 4. Detailed Implementation

[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0043] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0044] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0045] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0046] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0047] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0048] Unless otherwise specified, room temperature or ambient temperature in the following embodiments, comparative examples and test examples of this invention refers to 20-30 ℃.

[0049] All raw materials used in the following embodiments, comparative examples and test examples of this invention are commercially available products.

[0050] In the following embodiments and comparative examples of the present invention, step (1) in Examples 1-3 and Comparative Examples 3-4 is actually the same preparation process. That is, the waste lithium cobalt oxide cathode material solutions in Examples 1-3 and Comparative Examples 3-4 are actually the same batch of waste lithium cobalt oxide cathode material solutions. When performing ICP testing and cycle performance testing, the average value of three tests is taken as the data of this batch of waste lithium cobalt oxide cathode material solutions. Therefore, the ICP data of waste lithium cobalt oxide in Examples 1-3 are consistent, and the cycle performance of waste lithium cobalt oxide in Examples 1-3 and Comparative Examples 3-4 is consistent.

[0051] Similarly, step (1) in Comparative Examples 1-2 is actually the same preparation process, so the recycling performance of waste lithium cobalt oxide in Comparative Examples 1-2 is consistent.

[0052] Example 1 A short-process, non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials, comprising the following steps: (1) Discharge the waste lithium cobalt oxide battery to SOC=20% (deep discharge state) and then disassemble it to remove the positive electrode sheet. Citric acid and ethylene glycol are placed together in a reagent bottle at a mass ratio of 1:2. The mixture is heated to 80 °C and kept at this temperature for 30 min under magnetic stirring to form a clear and transparent solution. Then, it is cooled to room temperature to obtain DES. The removed positive electrode sheet is placed in DES (solid-liquid ratio of 1g:10mL, DES can completely immerse the positive electrode sheet), heated to 60 °C and kept at this temperature for 15 min. As a green medium composed of hydrogen bond donors and acceptors, DES can accurately disintegrate the three-dimensional bonding network of polyvinylidene fluoride binder under mild conditions, realizing the non-destructive separation of waste lithium cobalt oxide positive electrode material from the current collector. After the soaking is completed, the current collector is removed from the DES, leaving the waste lithium cobalt oxide positive electrode material in the DES to obtain a waste lithium cobalt oxide positive electrode material solution.

[0053] (2) Lithium nitrate, nickel nitrate, and manganese nitrate were weighed according to the molar ratio of metal elements Li:Ni:Mn = 1.05:0.5:1.5, and the molar ratio of Ni element in nickel nitrate to Co element in waste lithium cobalt oxide cathode material solution was 1:40. These were used as the lithium source, nickel source, and manganese source for lithium nickel manganese oxide (the lithium source was 5% in excess relative to the theoretical stoichiometric ratio of lithium nickel manganese oxide to compensate for lithium loss during subsequent high-temperature calcination). Then, they were added sequentially to anhydrous ethanol and stirred at room temperature until homogeneous to obtain a mixed solution (the concentration of Ni element in the mixed solution was 1.46%). (g / L); Subsequently, lithium nitrate was weighed as a supplementary lithium source for repairing the waste lithium cobalt oxide cathode material based on the lithium deficiency status of the waste lithium cobalt oxide cathode material solution (i.e., as a supplementary lithium source for the waste lithium cobalt oxide material). Specifically, the amount of supplementary lithium source was calculated according to the following formula: the molar amount of Li element in the supplementary lithium source = (the molar amount of Co element in the waste lithium cobalt oxide cathode material solution - the molar amount of Li element in the waste lithium cobalt oxide cathode material solution) × 1.05 (relative to the lithium deficiency status, the supplementary lithium source was 5% in excess to compensate for the lithium loss during the subsequent high-temperature calcination process); the weighed supplementary lithium source was added to the above mixed solution for a second room temperature mixing, and finally a clear liquid was obtained as the repair and regeneration solution.

[0054] (3) The repair and regeneration solution obtained in step (2) is slowly poured into the waste lithium cobalt oxide cathode material solution obtained in step (1) using a guide rod (the waste lithium cobalt oxide cathode material solution is kept heated at 60 °C). After the repair and regeneration solution is added, it is stirred continuously at 60 °C for 30 min. Then, while maintaining this temperature, ammonia is added dropwise to adjust the pH value to 7.0. After the pH stabilizes, the temperature is raised to 80 °C and stirring is continued until the anhydrous ethanol is completely evaporated, resulting in a mixed colloid.

[0055] (4) After the mixed colloid is thoroughly dried in a forced-air drying oven at 60 °C, it is mechanically ground to obtain a mixed powder. The mixed powder is placed in a tube furnace, and high-purity oxygen (99.999%, flow rate 200 sccm) is introduced into the tube furnace to create an oxidizing environment. Then, the temperature is raised to 850 °C at a heating rate of 5 °C / min and held for calcination for 22 h. Then, it is cooled to room temperature with the furnace. During the calcination process, residual organic matter is removed and the waste lithium cobalt oxide cathode material is regenerated in situ (including in-situ repair of lithium cobalt oxide and in-situ coating of lithium nickel manganese oxide), resulting in regenerated lithium nickel manganese oxide coated lithium cobalt oxide cathode material.

[0056] Figure 1 The XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment are shown below (where recycled lithium cobalt oxide represents recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material, and waste lithium cobalt oxide represents waste lithium cobalt oxide cathode material; the waste lithium cobalt oxide cathode material sample was obtained by filtration and drying of the waste lithium cobalt oxide cathode material solution obtained in step (1)). It can be seen that the original waste lithium cobalt oxide cathode material exhibits a significant Co3O4 (220) crystal plane characteristic peak (JCPDS No. 42-1467) at 2θ≈31.2°; while the Co3O4 peak of the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material completely disappears, and the lattice order is significantly restored. The main phase diffraction peak of the recycled material is completely matched with the standard layered structure of LiCoO2 (JCPDS No. 50-0653), indicating that there is no phase transition or impurity generation in the material. XRD patterns verify that the method of this invention can decompose PVDF at near-room temperature of 60 °C, and can successfully repair the damaged layered structure of LiCoO2 waste during subsequent calcination, ensuring its structural integrity. This is significantly better than the structural degradation caused by high-temperature calcination or traditional wet processes. Table 1 shows the ICP data of waste lithium cobalt oxide cathode material and recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment (where mass percentage refers to the mass content of each element in the waste material or recycled material, and the mass of waste lithium cobalt oxide cathode material is obtained by filtration, drying and weighing of the waste lithium cobalt oxide cathode material solution obtained in step (1)). It can be seen that the lithium deficiency (molar amount of 1-Ni element / molar amount of Co element) of the original waste lithium cobalt oxide cathode material is 0.25. The lithium-cobalt ratio of the recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material is restored to about 1. At the same time, due to the coating of lithium nickel manganese oxide, its lithium-cobalt ratio is slightly greater than 1. The nickel-manganese ratio conforms to the ratio of 0.5:1.5 in the chemical formula of lithium nickel manganese oxide. This also proves that the method of the present invention successfully repairs the damaged layered structure of LiCoO2 waste and successfully synthesizes lithium nickel manganese oxide.

[0057] Table 1 Furthermore, to further demonstrate the successful synthesis of the lithium nickel manganese oxide coating layer in the method of this invention, lithium nickel manganese oxide was also prepared separately by the sol-gel method and characterized by XRD in this embodiment. The specific preparation steps of lithium nickel manganese oxide are as follows: (1) Weigh lithium nitrate, nickel nitrate and manganese nitrate according to the molar ratio of metal elements Li:Ni:Mn=1.05:0.5:1.5 as lithium source, nickel source and manganese source of lithium nickel manganese oxide (the lithium source is 5% in excess relative to the theoretical stoichiometric ratio of lithium nickel manganese oxide to make up for the lithium loss in the subsequent high temperature calcination process), and then add them to anhydrous ethanol in sequence and stir at room temperature to mix evenly to obtain a mixed solution (the concentration of Ni element in the mixed solution is 1.46 g / L), which is used as the precursor solution.

[0058] (2) Stir the precursor solution obtained in step (1) at 60 °C for 30 min; then keep the temperature and add ammonia to adjust the pH to 7.0. After the pH stabilizes, raise the temperature to 80 °C and continue stirring until the anhydrous ethanol is completely evaporated to obtain the colloid.

[0059] (3) After the colloid was thoroughly dried in a forced-air drying oven at 60 °C, it was mechanically ground to obtain pre-sintered powder. The pre-sintered powder was placed in a tube furnace, and high-purity oxygen (99.999%, flow rate 200 sccm) was introduced into the tube furnace to create an oxidizing environment. Then, the temperature was increased to 850 °C at a heating rate of 5 °C / min and held for calcination for 22 h. The furnace was then cooled to room temperature to obtain lithium nickel manganese oxide material. The XRD pattern of the obtained lithium nickel manganese oxide material is shown below. Figure 2 As shown, its XRD pattern exhibits three strong diffraction peaks at 2θ = 18.78°, 36.41°, and 44.25°, corresponding to the (111), (311), and (400) crystal planes, respectively, with relative intensities of 100%, 55%, and 60% (with the strongest peak considered as 100%). The positions of the three strong peaks are consistent with those of JCPDS No. 32-0581 (LiNi 0.5 Mn 1.5 The O4 standard spectrum is consistent, and no characteristic peaks of impurity phases such as Li2CO3 and NiO (2θ=21.3°, 37.2°) were detected, indicating that lithium nickel manganese oxide was successfully synthesized and crystallized well. This shows that the method of the present invention can achieve lithium nickel manganese oxide coating while successfully repairing the damaged layered structure of LiCoO2 waste.

[0060] Example 2 Same as Example 1, except that the calcination temperature in step (4) is 900 ℃, that is, the temperature is raised to 900 ℃ at a heating rate of 5 ℃ / min and kept at that temperature for 22 h.

[0061] Figure 3The XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment are shown. It can be seen that the original waste lithium cobalt oxide cathode material exhibits a significant Co3O4 (220) crystal plane characteristic peak (JCPDS No. 42-1467) at 2θ≈31.2°; while the Co3O4 peak of the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material completely disappears, indicating a significant restoration of lattice order. The main phase diffraction peaks of the recycled material perfectly match the standard layered structure of LiCoO2 (JCPDS No. 50-0653), indicating that no phase transition or impurity generation occurs in the material. The XRD pattern results verify that the method of this invention can decompose PVDF at near-room temperature (60 ℃) and successfully repair the damaged layered structure of LiCoO2 waste during subsequent calcination, ensuring its structural integrity, which is significantly superior to the structural degradation problems caused by high-temperature calcination or traditional wet processes. Table 2 shows the ICP data of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment. It can be seen that the original waste lithium cobalt oxide cathode material has a lithium deficiency of 0.25%, while the lithium-cobalt ratio of the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material is restored to around 1. Furthermore, due to the coating of lithium nickel manganese oxide, its lithium-cobalt ratio is slightly greater than 1, and the nickel-manganese ratio conforms to the 0.5:1.5 ratio in the chemical formula of lithium nickel manganese oxide. This also proves that the method of this invention successfully repaired the damaged layered structure of the LiCoO2 waste and successfully synthesized lithium nickel manganese oxide.

[0062] Table 2 Example 3 Same as Example 1, except that the calcination temperature in step (4) is 950 ℃, that is, the temperature is raised to 950 ℃ at a heating rate of 5 ℃ / min and kept at that temperature for 22 h.

[0063] Figure 4The XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment are shown. It can be seen that the original waste lithium cobalt oxide cathode material exhibits a significant Co3O4 (220) crystal plane characteristic peak (JCPDS No. 42-1467) at 2θ≈31.2°; while the Co3O4 peak of the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material completely disappears, indicating a significant restoration of lattice order. The main phase diffraction peaks of the recycled material perfectly match the standard layered structure of LiCoO2 (JCPDS No. 50-0653), indicating that no phase transition or impurity generation occurs in the material. The XRD pattern results verify that the method of this invention can decompose PVDF at near-room temperature (60℃) and successfully repair the damaged layered structure of LiCoO2 waste during subsequent calcination, ensuring its structural integrity, which is significantly superior to the structural degradation problems caused by high-temperature calcination or traditional wet processes. Table 3 shows the ICP data of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material in this embodiment (where recycled lithium cobalt oxide represents recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material, and waste lithium cobalt oxide represents waste lithium cobalt oxide cathode material). It can be seen that the original waste lithium cobalt oxide cathode material has a lithium deficiency of 0.25, and the lithium-cobalt ratio of the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material is restored to around 1. Simultaneously, due to the coating of lithium nickel manganese oxide, its lithium-cobalt ratio is slightly greater than 1, and the nickel-manganese ratio conforms to the 0.5:1.5 ratio in the chemical formula of lithium nickel manganese oxide. This also proves that the method of this invention successfully repaired the damaged layered structure of LiCoO2 waste and successfully synthesized lithium nickel manganese oxide.

[0064] Table 3 Comparative Example 1 (1) Discharge the waste lithium cobalt oxide battery to SOC=20% (deep discharge state) and then disassemble it to remove the positive electrode sheet. Place the removed positive electrode sheet into a tube furnace and introduce high-purity oxygen (99.999%, flow rate 200 sccm) into the tube furnace to create an oxidation environment. Then heat it to 500 ℃ at a heating rate of 5 ℃ / min and keep it at that temperature for 5 h. Then cool it to room temperature with the furnace and collect the black powder (i.e. waste lithium cobalt oxide positive electrode material) calcined on the current collector.

[0065] (2) Weigh lithium nitrate as a supplementary lithium source for repairing the waste lithium cobalt oxide cathode material based on the lithium deficiency situation of the waste lithium cobalt oxide cathode material (i.e., as a supplementary lithium source for the waste lithium cobalt oxide material). Specifically, the amount of supplementary lithium source is calculated according to the following formula: the molar amount of Li element contained in the supplementary lithium source = (the molar amount of Co element contained in the waste lithium cobalt oxide cathode material - the molar amount of Li element contained in the waste lithium cobalt oxide cathode material) × 1.05; add the weighed supplementary lithium source to anhydrous ethanol and stir and mix evenly at room temperature to obtain a lithium nitrate solution (concentration of 0.249 mol / L).

[0066] (3) Heat the lithium nitrate solution obtained in step (2) to 60 °C under stirring, then add the black powder obtained in step (1), continue stirring at 60 °C until homogeneous, and then use ammonia water to quickly adjust the pH of the mixed solution to 7.0. After the pH stabilizes, raise the temperature to 80 °C and continue stirring until the anhydrous ethanol completely evaporates to obtain the mixed colloid.

[0067] (4) After the mixed colloid is fully dried in a forced-air drying oven at 60 °C, it is mechanically ground to obtain a mixed powder. The mixed powder is placed in a tube furnace, and high-purity oxygen (99.999%, flow rate 200 sccm) is introduced into the tube furnace to form an oxidizing environment. Then, the temperature is raised to 850 °C at a heating rate of 5 °C / min and held for calcination for 22 h. Then, it is cooled to room temperature with the furnace to obtain the regenerated lithium cobalt oxide cathode material.

[0068] The main difference between this comparative example and Example 1 is that the high-temperature calcination method is used to replace the DES separation electrode step; and the subsequent sol-gel method is used only to supplement the missing lithium source of the waste lithium cobalt oxide cathode material.

[0069] Figure 5 The XRD patterns of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material in this comparative example are shown. It can be seen that the original waste lithium cobalt oxide cathode material exhibits a significant Co3O4 (220) crystal plane characteristic peak (JCPDS No. 42-1467) at 2θ≈31.2°; while the Co3O4 peak in the recycled lithium cobalt oxide cathode material completely disappears, and the lattice order is significantly restored. The main phase diffraction peaks of the recycled material perfectly match the standard layered structure of LiCoO2 (JCPDS No. 50-0653), indicating that there is no phase transition or impurity formation in the material. Table 4 shows the ICP data of the waste lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material in this example. It can be seen that the lithium deficiency of the original waste lithium cobalt oxide cathode material is 0.24, and the lithium-cobalt ratio of the recycled lithium cobalt oxide cathode material is restored to the theoretical stoichiometric ratio of 1, proving that the sol-gel method can successfully repair the damaged layered structure of LiCoO2 waste without lithium nickel manganese oxide coating.

[0070] Table 4 Comparative Example 2 (1) Discharge the waste lithium cobalt oxide battery to SOC=20% (deep discharge state) and then disassemble it to remove the positive electrode sheet. Place the removed positive electrode sheet into a tube furnace and introduce high-purity oxygen (99.999%, flow rate 200 sccm) into the tube furnace to create an oxidation environment. Then heat it to 500 ℃ at a heating rate of 5 ℃ / min and keep it at that temperature for 5 h. Then cool it to room temperature with the furnace and collect the black powder (i.e. waste lithium cobalt oxide positive electrode material) calcined on the current collector.

[0071] (2) Lithium nitrate, nickel nitrate, and manganese nitrate were weighed according to the molar ratio of metal elements Li:Ni:Mn = 1.05:0.5:1.5, and the molar ratio of Ni element in nickel nitrate to Co element in waste lithium cobalt oxide cathode material was 1:40. These were used as the lithium source, nickel source, and manganese source for lithium nickel manganese oxide, respectively. Then, they were added to anhydrous ethanol and stirred at room temperature until homogeneous, resulting in a mixed solution (the concentration of Ni element in the mixed solution was 1.46%). (g / L); Subsequently, lithium nitrate was weighed as a supplementary lithium source for repairing the waste lithium cobalt oxide cathode material according to the lithium deficiency situation of the waste lithium cobalt oxide cathode material (i.e., as a supplementary lithium source for the waste lithium cobalt oxide material). Specifically, the amount of supplementary lithium source was calculated according to the following formula: molar amount of Li element contained in the supplementary lithium source = (molar amount of Co element contained in the waste lithium cobalt oxide cathode material - molar amount of Li element contained in the waste lithium cobalt oxide cathode material) × 1.05; The weighed supplementary lithium source was added to the above mixed solution and mixed at room temperature for a second time to obtain a clear liquid, which was used as the repair and regeneration solution.

[0072] (3) Heat the repair and regeneration solution obtained in step (2) to 60 °C under stirring, then add the black powder obtained in step (1), continue stirring at 60 °C until uniform, and then use ammonia water to quickly adjust the pH of the mixed solution to 7.0. After the pH stabilizes, raise the temperature to 80 °C and continue stirring until the anhydrous ethanol completely evaporates to obtain the mixed colloid.

[0073] (4) After the mixed colloid is fully dried in a forced-air drying oven at 60 °C, it is mechanically ground to obtain a mixed powder. The mixed powder is placed in a tube furnace, and high-purity oxygen (99.999%, flow rate 200 sccm) is introduced into the tube furnace to form an oxidizing environment. Then, the temperature is raised to 850 °C at a heating rate of 5 °C / min and held for calcination for 22 h. Then, it is cooled to room temperature with the furnace to obtain the recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material.

[0074] Comparative Example 3 (1) Discharge the waste lithium cobalt oxide battery to SOC=20% (deep discharge state) and then disassemble it to remove the positive electrode sheet. Put citric acid and ethylene glycol into a reagent bottle at a mass ratio of 1:2, heat to 80 ℃ under magnetic stirring and keep stirring for 30 min to form a clear and transparent solution, and then cool to room temperature to obtain DES. Put the removed positive electrode sheet into DES (solid-liquid ratio of 1g:10mL, DES can completely immerse the positive electrode sheet), heat to 60 ℃ and keep soaking for 15 min. After the soaking is completed, remove the current collector from DES, leaving the waste lithium cobalt oxide positive electrode material in DES to obtain the waste lithium cobalt oxide positive electrode material solution (the waste lithium cobalt oxide positive electrode material solution is kept heated to 60 ℃).

[0075] (2) Based on the lithium deficiency of the waste lithium cobalt oxide cathode material in the waste lithium cobalt oxide cathode material solution, weigh lithium nitrate as a supplementary lithium source for repairing the waste lithium cobalt oxide cathode material (i.e., as a supplementary lithium source for the waste lithium cobalt oxide material). Specifically, the amount of supplementary lithium source is calculated according to the following formula: the molar amount of Li element contained in the supplementary lithium source = (the molar amount of Co element contained in the waste lithium cobalt oxide cathode material solution - the molar amount of Li element contained in the waste lithium cobalt oxide cathode material solution) × 1.05; add the weighed supplementary lithium source to anhydrous ethanol and stir and mix evenly at room temperature to obtain a lithium nitrate solution (concentration of 0.249 mol / L).

[0076] (3) The lithium nitrate solution obtained in step (2) is slowly poured into the waste lithium cobalt oxide cathode material solution obtained in step (1) using a guide rod (the waste lithium cobalt oxide cathode material solution is kept heated at 60 °C). After the lithium nitrate solution is added, it is stirred continuously at 60 °C for 30 min. Then, while maintaining this temperature, ammonia is added dropwise to adjust the pH value to 7.0. After the pH stabilizes, the temperature is raised to 80 °C and stirring is continued until the anhydrous ethanol is completely evaporated, resulting in a mixed colloid.

[0077] (4) After the mixed colloid is fully dried in a forced-air drying oven at 60 °C, it is mechanically ground to obtain a mixed powder. The mixed powder is placed in a tube furnace, and high-purity oxygen (99.999%, flow rate 200 sccm) is introduced into the tube furnace to form an oxidizing environment. Then, the temperature is raised to 850 °C at a heating rate of 5 °C / min and held for calcination for 22 h. Then, it is cooled to room temperature with the furnace to obtain the regenerated lithium cobalt oxide cathode material.

[0078] Comparative Example 4 (1) Discharge the waste lithium cobalt oxide battery to SOC=20% (deep discharge state) and then disassemble it to remove the positive electrode sheet. Citric acid and ethylene glycol are placed together in a reagent bottle at a mass ratio of 1:2. The mixture is heated to 80 °C and kept at this temperature for 30 min under magnetic stirring to form a clear and transparent solution. Then, it is cooled to room temperature to obtain DES. The removed positive electrode sheet is placed in DES (solid-liquid ratio of 1g:10mL, DES can completely immerse the positive electrode sheet), heated to 60 °C and kept at this temperature for 15 min. After the soaking is completed, the current collector is removed from the DES, leaving the waste lithium cobalt oxide positive electrode material in the DES (to obtain a waste lithium cobalt oxide positive electrode material solution). The waste lithium cobalt oxide positive electrode material is then collected by vacuum filtration.

[0079] (2) Lithium carbonate, nickel oxide, and manganese oxide are weighed as lithium, nickel, and manganese sources for lithium nickel manganese oxide, with a metal element molar ratio of Li:Ni:Mn=1.05:0.5:1.5 and a molar ratio of Ni element in nickel nitrate to Co element in waste lithium cobalt oxide cathode material of 1:40. These are then mechanically ground with the waste lithium cobalt oxide cathode material obtained in step (1) at room temperature to obtain mixed powder 1. Subsequently, lithium nitrate is weighed as a supplementary lithium source for repairing the waste lithium cobalt oxide cathode material (i.e., as a supplementary lithium source for the waste lithium cobalt oxide material) according to the lithium deficiency of the waste lithium cobalt oxide cathode material. Specifically, the amount of supplementary lithium source is calculated according to the following formula: molar amount of Li element in supplementary lithium source = (molar amount of Co element in waste lithium cobalt oxide cathode material - molar amount of Li element in waste lithium cobalt oxide cathode material) × 1.05. The weighed supplementary lithium source is added to the above mixed powder 1 for secondary room temperature mechanical grinding to obtain mixed powder 2.

[0080] (3) Place the mixed powder 2 into a tube furnace, introduce high-purity oxygen (99.999%, flow rate 200sccm) into the tube furnace to form an oxidation environment, then heat it to 850 ℃ at a heating rate of 5 ℃ / min and keep it at that temperature for 22 h, and then cool it to room temperature with the furnace to obtain the recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material.

[0081] Test Example 1 Electrochemical performance testing: The waste lithium cobalt oxide cathode material and recycled material from each example and comparative example were used to assemble batteries for electrochemical performance testing. The specific assembly and testing methods are as follows: 2025-type button batteries were assembled in an argon-filled glove box and used for electrochemical testing. The electrochemical testing was carried out using a LAND battery testing system. The preparation method of the cathode in the 2025-type button battery is as follows: active materials (waste lithium cobalt oxide cathode material or recycled material; the waste lithium cobalt oxide cathode material in Examples 1-3 was obtained by filtration and drying of the waste lithium cobalt oxide cathode material solution obtained in step (1), Super C and PVDF were mixed in a weight ratio of 8:1:1, and then NMP was added as a solvent to prepare a slurry. The obtained slurry was coated on aluminum foil, vacuum dried at 120°C, and then cut into round pieces with a diameter of 13 mm to obtain the cathode. Lithium foil was used as the negative electrode of the battery, and a layer of polypropylene film (Celgard 2400) was used as the separator of the battery. The electrolyte used in the battery was purchased from DodoChemistry.com. Specifically, the electrolyte was obtained by dissolving LiPF6 at a concentration of 1 mol / L in a mixture of ethylenedicarbonate (EC) and diethylenedicarbonate (DEC) (volume ratio of 1:1).

[0082] The test results are as follows: Figure 6 The graph shows a comparison of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled nickel-manganese lithium-coated lithium cobalt oxide cathode material at 1C rate in Example 1. It can be seen that the first-cycle discharge specific capacity of the waste lithium cobalt oxide cathode material is only 179.8 mAh g. -1 The recycled material has a capacity of 222.4 mAh g. -1 The initial discharge specific capacity of the two batteries was 106.7 mAh g, and their discharge specific capacities after 100 cycles were 106.7 mAh g. -1 (waste materials) and 150.3 mAh g -1 (Recycled materials).

[0083] Figure 7 The graph shows a comparison of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled nickel-manganese lithium-coated lithium cobalt oxide cathode material at 1C rate in Example 2. It can be seen that the first-cycle discharge specific capacity of the waste lithium cobalt oxide cathode material is only 179.8 mAh g. -1 The recycled material has a capacity of 224.2 mAh g. -1 The initial discharge specific capacity of the two batteries was 106.7 mAh g, and their discharge specific capacities after 100 cycles were 106.7 mAh g. -1 (waste materials) and 165.8 mAh g -1 (Recycled materials).

[0084] Figure 8The graph shows a comparison of the long-cycle performance of the waste lithium cobalt oxide cathode material and the recycled lithium nickel manganese oxide-coated lithium cobalt oxide cathode material at 1C rate in Example 3. It can be seen that the first-cycle discharge specific capacity of the waste lithium cobalt oxide cathode material is only 179.8 mAh g. -1 The recycled material has 201.5 mAh g⁻¹ -1 The initial discharge specific capacity of the two batteries was 106.7 mAh g, and their discharge specific capacities after 100 cycles were 106.7 mAh g. -1 (waste materials) and 155.3 mAh g -1 (Recycled materials).

[0085] Figure 9 The graph shows a comparison of the long-cycle performance of the spent lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at 1 C rate in Comparative Example 1. It can be seen that the first-cycle discharge specific capacity of the spent lithium cobalt oxide cathode material is only 161.5 mAh g⁻¹. -1 The recycled material has a capacity of 206.5 mAh g. -1 The initial discharge specific capacity of the two batteries was 93.9 mAh g, and their discharge specific capacities after 100 cycles were 93.9 mAh g. -1 (waste materials) and 80.5 mAh g -1 (Recycled materials).

[0086] Figure 10 The graph shows a comparison of the long-cycle performance of the spent lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at a 1 C rate in Comparative Example 2. It can be seen that the first-cycle discharge specific capacity of the spent lithium cobalt oxide cathode material is only 161.5 mAh g⁻¹. -1 The recycled material has a capacity of 207.3 mAh g. -1 The initial discharge specific capacity of the two batteries was 93.9 mAh g, and their discharge specific capacities after 100 cycles were 93.9 mAh g. -1 (waste materials) and 106.2 mAh g -1 (Recycled materials).

[0087] Figure 11 The graph shows a comparison of the long-cycle performance of the spent lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at 1 C rate in Comparative Example 3. It can be seen that the first-cycle discharge specific capacity of the spent lithium cobalt oxide cathode material is only 179.8 mAh g⁻¹. -1 The recycled material has a capacity of 193.2 mAh g. -1 The initial discharge specific capacity of the two batteries was 106.7 mAh g, and their discharge specific capacities after 100 cycles were 106.7 mAh g. -1 (waste materials) and 68.5 mAh g -1 (Recycled materials).

[0088] Figure 12 The graph shows a comparison of the long-cycle performance of the spent lithium cobalt oxide cathode material and the recycled lithium cobalt oxide cathode material at 1 C rate in Comparative Example 4. It can be seen that the first-cycle discharge specific capacity of the spent lithium cobalt oxide cathode material is only 179.8 mAh g⁻¹. -1 The recycled material has a capacity of 220.8 mAh g. -1 The initial discharge specific capacity of the two batteries was 106.7 mAh g, and their discharge specific capacities after 100 cycles were 106.7 mAh g. -1 (waste materials) and 80.5 mAh g -1 (Recycled materials).

[0089] By comparing Example 1 with Comparative Examples 1-4, it can be seen that using the method of the present invention for the non-destructive separation and regeneration of waste lithium cobalt oxide cathode materials can better give full play to the ultra-high capacity of lithium cobalt oxide cathode materials under high pressure.

[0090] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A short-process, non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials, characterized in that, Includes the following steps: The positive electrode sheet recovered from the waste lithium cobalt oxide battery is heated and soaked in a eutectic solvent to separate the waste lithium cobalt oxide positive electrode material from the current collector. After the current collector is removed, a solution of waste lithium cobalt oxide positive electrode material is obtained. A remediation and regeneration solution containing nickel, manganese, and lithium is added to the waste lithium cobalt oxide cathode material solution, heated and stirred, and then the pH of the mixed solution is adjusted to 6-9 before being heated to volatilize, resulting in a mixed colloid. The mixed colloid is dried, ground, and then calcined to obtain recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material, thus achieving non-destructive separation and regeneration of waste lithium cobalt oxide cathode material.

2. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The hydrogen bond acceptors of the eutectic solvent include citric acid, salicylic acid, phytic acid, or lactic acid, and the hydrogen bond donors include ethylene glycol, xylitol, glycerol, or glycerol.

3. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 2, characterized in that, The mass ratio of the hydrogen bond acceptor to the hydrogen bond donor is in the range of 1:2 to 1:

4.

4. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The heating and soaking treatment is carried out at a temperature of 60-120 ℃ for 5-30 min.

5. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The preparation steps of the remediation and regeneration solution containing nickel, manganese, and lithium include: weighing the lithium source, nickel source, and manganese source of lithium nickel manganese oxide according to the molar ratio of metal elements Li:Ni:Mn=1.05:0.5:1.5 and the molar ratio of nickel element in the nickel source to cobalt element in the waste lithium cobalt oxide cathode material solution is 1:40; weighing the supplementary lithium source of the waste lithium cobalt oxide cathode material according to the molar amount of lithium element in the supplementary lithium source = (molar amount of cobalt element in the waste lithium cobalt oxide cathode material solution - molar amount of lithium element in the waste lithium cobalt oxide cathode material solution) × 1.05; and mixing the lithium source, nickel source, manganese source, and supplementary lithium source with anhydrous ethanol to obtain the remediation and regeneration solution containing nickel, manganese, and lithium.

6. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The temperature for heating and volatilization is 60-100 ℃.

7. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The calcination process includes: heating to 800-1000 ℃ at a heating rate of 1-10 ℃ / min and then holding at that temperature for calcination for 10-24 h.

8. The short-process non-destructive separation and regeneration method for waste lithium cobalt oxide cathode materials as described in claim 1, characterized in that, The calcination process is carried out in an oxygen-containing atmosphere.

9. A recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material obtained by the short-process waste lithium cobalt oxide cathode material non-destructive separation and regeneration method as described in any one of claims 1-8.

10. The application of the recycled lithium nickel manganese oxide coated lithium cobalt oxide cathode material as described in claim 9 in the preparation of lithium cobalt oxide batteries.

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